I was just reading an advertisement about Oregon parts. The ad about their R50 blades states the blades will stay sharper 10- 15% longer due to their hardening process. They also claim improved durability, longer blade life and better cutting performance. The blades are also straightened after the manufacturing process. I have noticed that all the blades Ive ordered from Mow More are bowed almost 1/8 in the middle. Has anyone else noticed this or used the Oregon R50's and noticed any difference in cut quality?